Backfire torch



March 17, 1964 w. LINDGREN BACKFIRE TORCH 2 Sheets-Sheet 1 Filed Dec. 6, 1961 United States Patent Office 3,125,153 Patented Mar. 17, 1964 3,125,153 BACKFIRE TORCH William L. Lindgren, Sycamore, Ill., assignor to Turner Corporation, Sycamore, 111., a corporation of Illinois Filed Dec. 6, 1961, Ser. No. 157,378 Claims. (Cl. 158-33) This invention rel-ates generally to an LP. or liquefied petroleum appliance, and more specifically to a torch which is particularly adapted for use in combatting and controlling forest and brush fires as for example in setting back fires.

In accordance with the invention, a backfire torch is 1 provided with a handle having a valvemechanism associated therewith and an elongated tube is connected thereto so a burner torch may be carried and manipulated by a user but the flame can be applied to a point of utilization with great facility. A windshield is provided for the burner head of the torch. To promote ease of handling, a portion of the conduit between the tank and the burner head is formed in the configuration of a pistol grip. The valve mechanism is positioned immediately against the grip for ready access by the user. Suitable connections are formed to supply gas from -a liquid propane bottle or the like either attached directly to the handle or communicating with a source of supply remote therefrom by means of a hose and adapter structure.

Further in accordance with the invention, a valve and lever assembly is provided which includes means for reducing the amount of angular movement of the needle for the valve, and positively preventing rotation of the needle. Thereby, leakage at an O-ring [for the needle valve during operation of the torch is eliminated. This advantageous construction is afforded by provision of a hole through the shank of the needle of the valve contacted by a pin pressed into a lever for the valve.

Accordingly, it is an object of the present invention to provide a backfire torch or the like which is simple to handle and easy to maneuver, which afliords a uniform flame by means of lever locking means and windshield means therefor, and which is exceptionally safe as a result of the windshield means and positioning of the burner assembly on an elongated tube and filler rod construction.

Another object of the invention is to provide a device as described which can be directly connected with a portable fuel container through a pistol handle grip thereof, as set forth, or with a fuel container disposed at a remote location and connected to the pistol grip handle through a hose construction.

Another object of the invention is to provide a device as described which has a valve and lever assembly maintainable in operative position by lock means connected with the handle thereof, and which also is effective to prevent leakage so as to assist in maintaining the uniform flame described during operation, and preserve fuel and FIGURE 1 is a side elevational view, partly brokenaway, of a backfire torch according to the present invention;

FIGURE 2 is an enlarged vertical sectional view of the burner head assembly of the structure shown in FIG- URE 1;

FIGURE 3 is an enlarged vertical sectional view of the valve and adapter assembly of the structure shown in FIGURE 1 for connection with a source of supply;

FIGURE 4 is a representation, partially in vertical seca source of supply for the structure shown in FIGURE 1;

FIGURE 5 is an enlarged vertical sectional View, partly broken away, of the valve and lever assembly shown in FIGURE 1 and FIGURE 6 is a vertical, sectional, tiragmental view of another embodiment of the windshield of the inventron.

Referring now to the drawings, and to FIGURE 1 in particular, a backfire torch assembly 10 is shown according to the present invention which includes a handle assembly v11 [for transmitting a supply of fuel from a source such as the bottle 12 of liquefied petroleum fuel such as propane or the like to a burner head assembly 13, by means of a valve and adapter assembly 1'4 connecting the source of supply 12 to the handle assembly C11. The flow of fuel is controlled by a valve and lever assembly 15 communicating with the opposite end of the handle assembly 11 and thus with an elongated tube and filler rod assembly 16 which supports the burner head assern bly 13 in a desirable spaced relation to the valve and lever assembly 15-.

There is thus formed between the fuel container 12 and the burner head 13 a fuel passage of substantial extent. It is contemplated that :a portion of the fuel passage forming means be enlarged and configured to form a handle particularly suited for manual grasping. Thus, the handle 11 provides such enlargement preferably through a molded or otherwise preformed boss shaped in the configuration of a pistol grip.

Further, in accordance with the invention, and as hereinafter described, the handle assembly 11 carries a pivotal lock 17, which may be of U-shaped construction for sewhich is maintained by a windshield 18 in the burner head assembly. For continued usage the control knob of a rotatably adjustable valve could be operated, however,

- the pivotal lock 17 cooperates with a trigger-operated actuator associated with the valve whereby the torch may be conveniently flipped instantly between a pilot flame operation and a full flame operation.

It will be noted that the pistol grip handle assembly 11 includes a ribbed back surface 19 intended to engage the palm of the user and a general body structure conforming to the hand of a user including a smooth finger surface 19a. Spaced protuberances 19b and 19c on opposite ends of the gripping surfaces prevent the device from sliding out of the grip of the user. The bottle 12 may conveniently comprise a throw away container of propane fuel readily carried in immediate association with the backfire torch structure, and gas is supplied through a passage (not shown) in the handle assembly 11 from the bottle or container by means of the valve and adapter assembly 14, which includes a valve body 20 having a skirt 21 releasably threaded on the neck 22 of the bottle 12.

As shown in FIGURES l and 4 an adapter member or the like 23 is threaded or otherwise secured in the handle assembly 11 in communication with the passage therein,

- and has an internally chamfered end 24 and an exteriorly threaded surface 25. In order to effect communication between the body portion 20 and the handle, a nipple 26 construction 29 in the retainer corresponding to a comtion and partially broken away, of a hose connection for" plementary stepped construction in the nipple.

The fuel from the bottle 12 is transmitted through a pusher pin 30 threaded in a bore 31. A gasket 32 held by a retainer 33 engages and seals against the neck 22 of the bottle 12. The pin 30 has a shoulder which seals against a surface of the valve body 20. Thence the fuel may flow through a passage 35 having a portion 36 opening into a valve seat 37 of the valve chamber 38. Flow passes from the valve chamber 38 to the bore 27 through a short passage 39, and this flow is turned on or off by a valve assembly 40 having a needle 41 retractably engageable with the valve seat 37 and axially positioned by a knurled handle or control knob 42 and a threaded boss 43 received in a correspondingly threaded, enlarged extension 44 of the valve passage or chamber 38. The boss 43 may be positioned on a stem 45 received in a fitting 46 also threaded in the bore 44, and in order to maintain a firm interfitting engagement of the threads on the valve stem, the upper portion of the stem may have a helical spring 47 wound therearound bearing against the fitting 46 and against the handle 42. It will however, be appreciated that variations in this construction may be accommodated within the scope of the invention, as understood by those skilled in the art.

Referring now to FIGURE 4, a further form of the invention is shown which may be used as a relatively large semi-portable bottle or container 12a propane fuel or the like. In this embodiment, an adapter 48 may be engaged by the retainer 28 in abutting relation with the nipple 26. A hose 49 of any desired length is connected thereto and to the adapter or connection 23. Thereby, the backfire torch may be moved readily in a relatively large area as determined by the length of the hose, without the need for lifting the container of fuel. In this form of the invention, of course, it is possible to use the adapter 48 in direct substitution for the adapter 23 and to secure a hose thereto, with a further adapter engaged by the retainer 28, and other constructions for affording maneuverability by means of a hose between the bottle and backfire torch are encompassed within the scope of the invention.

Referring now to FIGURE 5, after the fuel has passed through the handle assembly 11, it is manually controlled in regular operation by the valve and lever assembly 15. To this end, a fitting 50 is connected with the handle assembly 11 and has an externally threaded portion 51 on which the body 52 of the assembly is threaded by means of a skirt portion 53 thereof, as seen in FIGURE 1.

The body portion 52 alfords flow therethrough by way of a pusher pin 54 threaded in an inlet opening 55, and the fuel flows from the inlet to an outlet 56 through a passage 57 communicating with a valve chamber 58 having a valve seat 59, and thence through the passage 60.

In accordance with the invention, flow through the valve chamber 58 is controlled by a needle assembly 61 having a needle 62 retractably engageable linearly with the valve seat 59 as operated by a lever 63, as hereinafter further described. To position the needle valve 62 for axial movement, a pilot knob structure 64 is threaded into the valve body 52 at an enlarged bore portion 65 thereof. The pilot knob has an internal bore 66 with a reduced portion 67 slidably receiving a stem 68 of the needle; and the stem is also guided by a guide ring 69 threaded in the pilot knob 64, at the upper end of the enlarged bore 66. The ring 69 may be staked at one or more locations relative to the knob 64 to lock the parts against relative rotation.

In order to urge the needle 62 into closing relation with the valve seat 59, a spring 70 of preferably helical construction is disposed in surrounding relation to the stem 68 and bears at its lower end against a washer 71 which is seated on an annular flange 72 and at its upper end against the ring 69. The washer 71 is preferably of a suitable plastic material such as polyfluoroethylene or a like material. Also, a Washer 73 may be provided as retained by a retaining ring 74.

The valve thus afforded is sealed by an O-ring 75 in an enlarged portion 76 of the chamber 58, the O-ring being in resiliently sealing relationship with the needle valve 62 and with the walls of the chamber 76. In order to prevent leakage in a positive manner at the O-ring 75, during operation of the torch, the-invention provides for reduc ing angular movement of the needle, and for positively preventing rotation of the needle.

The valve stem 68 has a barrel portion which conformably slides in the bore walls of the ring 69. On the outer end of the stem 68, an actuator portion 68a is formed which includes convergent recessed portions 68b leaving a flat wall formed with a through aperture 77. The lever 63 is utilized to anchor the needle against rotation by means of a. pin 78 received in firm assembly within a pin recess 78a and extending into a cup-shaped head 79 formed on the end of the lever 63. The actuator end 68a also extends into the head 79 and the pin 78 is received in the aperture 77 The head 79 may be open at 80 to afford access to the pin 78.

The lever 63 in turn is pivotally mounted on an upstanding boss 81 on the skirt 53 by means of a suitable retention element or pin 82 extending through depending ears 83 on the lever, as seen in FIGURE 1. These ears serve to maintain the lever 63 in a substantially uniform axial alignment, while the lever 63 pivots on the boss 81 to actuate the needle reciprocably toward and away from the valve seat.

Further, in accordance with the invention, the lever 63 has a handle portion 84 which extends upwardly and rearwardly from the head 79. In order to maintain the lever 63 in open position when desired the U-shaped lock 17, which has lower inwardly turned ends or other pivotal mounting means engaging the handle 11, may be swung or rotated clockwise over the upper portion 84a of the handle, so that the user of the backfire torch can operate without interruption or any need for attention as to the extent of opening of the backfire torch valve assembly 15. Further, the lock 17 permits the operator to instantly flip the torch from a pilot to a full flame operation and vice versa.

The burner assembly head 13 receives flow from the assembly 15 by means of the elongated tube and filler rod assembly 16 which in its form of the invention shown in FIGURE 2, includes an outer tube portion 85 and an inner tubular rod 86, although it will be appreciated that a unitary tubular structure could be provided. In any event, the burner head assembly 13 is held in spaced relation to the lever and valve assembly 15 by the rigid tubular construction thus afiorded, with the tube and rod assembly 16 having an outwardly, downwardly and outwardly, substantially angular construction for this purpose and to maintain the burner asembly in a desirable relation to the user. The filler rod assembly not only adds strength to the assembly, but reduces the volume of gas in the tube 85, thereby giving a quicker and more positive control.

' The outlet port 56 of the valve body 52 therefore receives the elongated tube and filler rod assembly 16 by means of a compression nut 87 threaded in the outlet 56 against a compression ring 88 to aiford a secure seal.

The filler rod, at the outer end thereof, may terminate in proximately spaced relation to the end of the tube 85, and the engagement of this assembly with the burner head assembly 13 is thus provided by a retainer 89 threaded in a burner 90 of the assembly 13, the retainer 89 being threaded to the tube 85, or alternately having an elongate sleeve 91 as seen in FIGURE 6, which may overlap the end of the filler rod 86. At the same time, the tube is in secure sealing relationship with an inner passage 92 (or 92a in FIGURE 6) formed in the retainer 89. An orifice block 93 is threaded in the retainer 89 as shown and the burner is provided with an enlarged passage portion 95 and reduced burner outlet 96 in the head portion 97. Extending axially outwardly the outlet 96 has divergent tapered Walls 96a terminating in axially extending cylindrical walls 99. Openings 98 are formed through the head 97 to supply combustion supporting air for mixture with the vaporized fuel at the burner head. The cylindrical wall 99 forms a combustion chamber C and has formed therein plural circumferentially spaced openings 100 extending radially therethrough.

To protect the combustion chamber C thus afforded, the windshield 18 is mounted on a retainer ring 161. The ring 161 has a radial wall 102 and an annular axial portion forming a sleeve 103. The windshield 18 is pressed onto the burner at 97 and is secured in firm assembly with a set screw 104.

The windshield desirably is of an elongated cylindrical construction. The radial wall 102 extends radially outwardly sufiiciently to space the windshield concentrically outwardly of the cylindrical wall 99 thereby forming an annular zone 110 which communicates with the combustion chamber C via the openings 1%. The Windshield 18 at one end is crimped to engage the retainer 101 at preferably equally angularly spaced locations as afiorded by dimples or depressions 105 in the wall 102 of the retainer thereby to place the same in firm assembly with the burner head at its opposite end, the windshield 18 has an end wall 111 forming an outlet throat for the torch which 'is spaced axially outwardly of an end wall 112 formed on the end of the wall 99.

Further to provide a desirable fuel-air mixture, the wall 102 may define a plurality of axially extending openings 106 therethrough, as seen in FIGURE 6, communicating with the openings 93 and, as will be seen, with the openings 100. Thus, although a windshield is provided, extensive ventilation for burning purposes is afforded in a manner which minimizes interference from air turbulence induced by the manner in which the torch is manipulated during use or to which the torch is subjected because of environmental operating conditions.

Since the Windshield 18 desirably extends forwardly somewhat beyond the forward end of the cylindrical wall 99, as stated, it thereby acts as a guide and protection for the flame at the outer end of the torch.

Although minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. In a torch, a handle, a valve assembly on said handle, means communicating with said handle and said valve assembly for supplying fuel thereto, a tubular structure connected to said valve assembly and a burner connected to said tubular structure in spaced relation to said valve assembly, said burner including a burner head having an inlet end and an outlet end with a passage therethrough including an inner portion adjacent the tube and an outer portion of relatively wide dimension defined by a wide sleeve portion of the burner head and a windshield surrounding said burner in radially spaced relationship thereto and including an elongate cylindrical shield extending axially beyond the outlet end of the burner head and means connecting the shield to the burner head at the inlet end thereof, said burner head having apertures in the inner passage portion communicating with the space between the elongate shield and the burner head and apertures in the outer passage portion communicating with the space between the shield and the burner head, said means connecting the shield to the burner head comprising a wall secured to the burner head and extending radially outwardly thereof, means connecting the shield to the wall and a plurality of openings in the wall to increase ventilation within the shield.

2. In a propane appliance, an elongated conduit forming means comprising coupling connections for attach ment to a source of fuel and to a device for burning the fuel separated from one another and having a passage extending on a longitudinal axis disposed therebetween, a portion of said conduit forming means being enlarged to form a pistol-grip handle boss, said boss having a back surface spaced radially outwardly of said axis and being curved to engage the palm of a user when the boss is manually grasped, said boss further including a smooth finger surface spaced radially outwardly on the opposite side of said axis and being curved to engage the fingers of the user when the boss is manually grasped, said boss having a general body structure adapted forconforming to the hand of the user, spaced protuberances on opposite longitudinal ends of said finger surface to prevent the handle boss from slipping out of the grip of the user, and a valve in said passage having actuator means extending into an area immediately adjacent said back surface of said handle for ready thumb actuation by the user of the appliance, thereby to afford a simultaneous pistol gripping of the handle while regulating the How of fuel through the passage.

3. In a propane appliance as defined in claim 2, said actuator means comprising a lever pivotally mounted on said valve for operating the valve to open and close communication through said conduit means, and said lever having a lower portion adjacent the valve and an upwardly and outwardly extending portion adjacent said back surface, and a U-shaped lock pivoted to one end of said handle boss with the bight providing an outer end an having an inoperative position wherein the outer end is resting against the lower portion of the lever adjacent the valve and an operative, locking position wherein the outer end is engaged with the upwardly and outwardly extending lever portion to maintain the lever in valve opening position.

4. In a backfire torch, an elongated conduit means comprising coupling connections at opposite ends thereof for attachment to a source of fuel and to a burner head for burning the fuel remotely from the source of fuel, said conduit means forming a passage extending on a longitudinal axis between the source of fuel and the burner head, a portion of said conduit forming means being enlarged to form a pistol-grip handle boss having a back surface spaced radially outwardly of said axis and being curved to engage the palm of a user and further including a smooth finger surface spaced radially outwardly on the opposite side of said axis and being curved to engage the fingers of the user, said boss having a general body structure conforming to the hand of the user when the boss is manually grasped, spaced protuberances on opposite longitudinal ends of said finger surface to prevent the handle boss from slipping out of the grip of the user, a valve in said passage at one end of said handle boss and having actuator means extending into an area immediately adjacent said back surface of said handle boss for ready thumb actuation by the user of the backfire torch, thereby to simultaneously pistol-grip the handle boss while regulating the flow of fuel through the passage to the burner head, a tubular member on said valve supporting said burner head in spaced relation to said valve and including an outer tube and an inner rigid rod defining a passage therethrough, said outer tube and said inner rigid rod each having a complementary angular configuration for maintaining a desired position of said burner relative to said handle boss.

5. In a propane appliance, an elongated conduit forming coupling connections for attachment to a source of fuel and to a device for burning the fuel separated from one another and having a passage extending on a longitudinal axis disposed therebetween, a portion of said conduit forming means being enlarged to form a pistol grip handle boss, said boss having a back surface spaced radially outwardly of said axis and being curved to engage the palm of a user when the boss is manually grasped, said boss further including a smooth finger surface spaced radially outwardly on the opposite side of said axis and being curved to engage the fingers of the user when the boss is manually grasped, said boss having a general body structure adapted for conforming to the hand of the user, spaced protuberances on opposite longitudinal ends of said finger surface to prevent the handle boss from slipping out of the grip of the user, and a valve in said passage having actuator means including a rotatable knob extending into an area adjacent said handle for actuation by the user of the appliance, thereby to afford pistol gripping of the handle and flow regulation of fuel through the passage.

References Cited in the file of this patent UNITED STATES PATENTS 8 Falligant July 13, 1954 Balmer July 31, 1956 Lindgren June 2, 1959 Lindgren Nov. 1, 1960 FOREIGN PATENTS Great Britain Feb. 24, 1960 France Apr. 1, 1935 (Addition to No. 776,594) France May 26, 1928 France Nov. 8, 1934 France June 8, 1959 Germany Mar. 10, 1952 Germany Nov. 8, 1956 

2. IN A PROPANE APPLIANCE, AN ELONGATED CONDUIT FORMING MEANS COMPRISING COUPLING CONNECTIONS FOR ATTACHMENT TO A SOURCE OF FUEL AND TO A DEVICE FOR BURNING THE FUEL SEPARATED FROM ONE ANOTHER AND HAVING A PASSAGE EXTENDING ON A LONGITUDINAL AXIS DISPOSED THEREBETWEEN, A PORTION OF SAID CONDUIT FORMING MEANS BEING ENLARGED TO FORM A PISTOL-GRIP HANDLE BOSS, SAID BOSS HAVING A BACK SURFACE SPACED RADIALLY OUTWARDLY OF SAID AXIS AND BEING CURVED TO ENGAGE THE PALM OF A USER WHEN THE BOSS IS MANUALLY GRASPED, SAID BOSS FURTHER INCLUDING A SMOOTH FINGER SURFACE SPACED RADIALLY OUTWARDLY ON THE OPPOSITE SIDE OF SAID AXIS AND BEING CURVED TO ENGAGE THE FINGERS OF THE USER WHEN THE BOSS IS MANUALLY GRASPED, SAID BOSS HAVING A GENERAL BODY STRUCTURE ADAPTED FOR CONFORMING TO THE HAND OF THE USER, SPACED PROTUBERANCES ON OPPOSITE LONGITUDINAL ENDS OF SAID FINGER SURFACE TO PREVENT THE HANDLE BOSS FROM SLIPPING OUT OF THE GRIP OF THE USER, AND A VALVE IN SAID PASSAGE HAVING ACTUATOR MEANS EXTENDING INTO AN AREA IMMEDIATELY ADJACENT SAID BACK SURFACE OF SAID HANDLE FOR READY THUMB ACTUATION BY THE USER OF THE APPLIANCE, THEREBY TO AFFORD A SIMULTANEOUS PISTOL GRIPPING OF THE HANDLE WHILE REGULATING THE FLOW OF FUEL THROUGH THE PASSAGE. 